Gaseous electric discharge device



July 23, 1935. H. BAUM HAUER El AL GASEOUS ELECTRIC DISCHARGE DEVICE Filed March 5, 1935 INVENTORS 25M @awnzwz/ A ORNEY Patented duty 23, 1935 I FFICE Wiegand,

Berlin- Tempelhof,

Germany, as-

signors to General Electric Company, a corporation of New York Application March 5, 1935, Serial No. 9,515

lin Germany March 9, 1934 g 2 Claims.

The present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to gas feeding means for replenishing the gas filling of gaseous electric discharge devices.

Gaseous electric discharge devices having a filling of common gas or gases, such as carbon dioxide, nitrogen or hydrogen, require gas re plenishments for a useful life of the device since the common gas is rapidly consumed during the operation of the device. A successful gas replenishment means for such devices comprises a valve interposed between a gas reservoir and the container of the discharge device. The valve is controlled by the current flowing in the discharge device which, in turn, is determined by the gas pressure in the discharge device. A decrease in gas pressure causes an increase in the current load which causes the valve to open and permit the flow of gas from the reservoir to the container of the discharge device. When the gas pressure is restored the current load drops and the valve closes to interrupt the flow of gas into the container. A suitable valve in an apparatus of this type is one comprising a gas pervious element, such as a carbon cone, immersed in a liquid, a float which is movable in the liquid and an electro-magnet which controls the movements of the float and which is connected to the discharge device in such manner that the float rises when the current load increases and drops when .the current load decreases. The level of the liquid is thus changed and when the float rises the tip of the cone is exposed and gas flows into the container of the discharge device. When the float drops the flow of gas is interrupted. Oil and mercury are useful liquids in such a valve, the latter is somewhat preferable to the former as it is a more effective gas lock and does not stop-up the pores of the carbon cone.

The above described apparatus is suitable for laboratory purposes but is not practical commercially due to the diificulties encountered in shipping the same. These difliculties arise from the fact that the carbon cone is exposed and the gas flows from the reservoir to the container when the level of the liquid is changed due to changes in position of the apparatus or shocks thereto occurring during shipment. Attempts to 50 overcome this difllculty by so proportioning the valve chamber, the carbon cone and the amount of the liquid that even though the valve is tipped the cone is immersed in the liquid have failed due to the fact that such proportioning does not avoid gas leakage through the valve since the liquid is splashed when subjected to sudden shocks during shipment which exposes the carbon cone. Another hazard in shipping such devices is that the float, which is free to move in the valve, will break the valve chamber when the apparatus is moved suddenly.

The object of the present invention is to provide an automatic gas feeding apparatus for an electric discharge device which is capable of being shipped safely and without leakage. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

The invention attains its objects by using a gas impervious material which is solid at room temperatures and liquid at higher temperatures such as 40 to 100 0., such as a bismuth alloy, as the liquid element and by providing a heater element in operative relation to the valve chamber to maintain said alloy at a liquid temperature during the operation of the gaseous electric discharge device.

The apparatus can thus be shipped without gas seepage from the reservoir to the gaseous electric discharge device since the carbon cone is encased in the solidified metal and cannot leak no matter what the position of the apparatus or the shocks to which it is subjected during shipment. The float is fixed in the solidified metal which avoids the hazard of the float puncturing the walls of the valve chamber during shipment. The operation of the new and improved valve, after the alloy has been heated to the temperature at which it is liquid, is the same as that of valves of the same type described above having a material liquid at low temperatures therein. The heater element, such as an electric resistance is inexpensive and costs little to operate compared to the cost of the apparatus.

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown in a front elevational, partly sectional view.

Referring to the drawing the new and novel valve consists of a tube 2 which serves to conduct the gas and is connected with the illuminating tube I, which is to be fed, which tube 2 has a contracted part 3 into which a gas pervious carbon cone 5 is mounted by means of a suitable gas impervious sealing cement 4. The expanded part 6 of the tube 2 which is above the constriction 3 forms the valve chamber. The lower part of the latter is filled with a mass I of an alloy, which is solid at normal temperature but which melts even at very low temperature, for instance 9. bismuth alloy, to such an extent that the carbon cone 5 is completely covered or enclosed in the metal alloy. The float body of the valve consists, in the well known manner, of a small metal tube 8 the lower end of which is in the metal alloy. The upper end of this small tube is in the field of an electro-magnet winding 9 which surrounds the valve chamber 6. The electro-magnet winding 9 is connected to the illuminating tube in such manner that a change in the current load on the tube causes a corresponding change in the strength of the magnetic force exerted by the winding 9. By means of a tube I0 which is attached to the valve chamber, connection is established between the valve chamber and a storage container for the refeeding gas or a point of production of the gas. The lower part of the valve chamber 6 which contains the metal alloy 1 is surrounded by an electric heater wire winding I I which is connected to a source of current and which is switched on when the illuminating tube is put into operation and which liquefies the metal alloy I. During the operation of illuminating tube when the gas pressure in the tube I sinks the electro-magnet 9 is excited by the rise in the current load and by this excitation the small tube 8, which now is swimming freely in the metal alloy, is lifted. The level of the liquid metal alloy drops and the point of the carbon cone 5 is exposed. The gas then flows from the reservoir through the tube I0, the valve chamber 6, the carbon cone 5 and the tube 2 into the illuminating tube I.

When the gas pressure is restored in the tube I the current load diminishes, the float 8 drops, the level of the liquid alloy rises until the cone 5 is completely covered and the flow of gas from the reservoir or generator into the illuminating tube I is interrupted. When the gas pressure again drops the above operation is repeated.

The illuminating tube I is of any type known in the art and consists of an elongated tube having electrodes sealed therein at each end thereof which electrodes are cold electrodes or thermionic electrodes when desired.

While we have shown and described and have pointed out in the annexed claims certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States, is:-

1. A valve for feeding gas replenishments to a gaseous electric discharge device comprising a gas impervious element a gas pervious element covered by said gas impervious element, said gas impervious element being solid at temperatures lower than approximately 40 C. and liquid at temperatures between approximately 40 C. to C., means to heat said gas impervious element to a temperature at which said element is'in the liquid state, and means responsive to changes in current flow in said discharge device to change the level of said gas impervious element whereby gas replenishments are fed to the discharge device.

2. A valve for feeding gas replenishments to a gaseous electric discharge device comprising a gas impervious element a gas pervious element covered by said gas impervious element, said gas impervious element being a bismuth alloy solid at temperatures lower than approximately 40 C. and liquid at temperatures between approximately 40 C. to 100 C., means to heat said gas impervious element to a temperature at which said element is in the liquid state, and means responsive to changes in current flow in said discharge device to change the level of said gas impervious element whereby gas replenishments are fed to the discharge device.

HEINRICH BAUMHAUER. KURT WIEGAND. 

